Magneto-electric generator.



R. A. OGLESBY.

MAGNETO ELECTRIC GENERATOR. APPLICATION FILED FEB-23.1915- 1,262,692. Patented Apr. 16, 1918.

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unrrnn RICHARD A. OGLESBY, OF SOUTH BEND, INDIANA, ASSIGNOR TO QUICK ACTION IGNITION STATES PATENT OFFICE.

COMPANY, OF SOUTH BEND, INDIANA, A CORPORATIONOF INDIANA.

MAGNETIC-ELECTRIC GENERATOR.

Specification of Letters Patent. Patgnted Apr. 16, 1918.

Application filed February 23, 1915. Serial No. 10,005.

To all whom it may concern:

Be it known that RICHARD A. OGLESBY, citizen of the United States, residing at South Bend, in the county of St. Joseph and State of Indiana, has invented certain new and useful Improvements in Magneto- Electric Generators, of Which the following is a specification.

My invention relates to improvements in magneto electric generators and it appertains more especially to the features pointed out in the annexed claims.

The purpose of my invention is to provide a simple, compact and highly eificient electric generator of the magneto type in which contrary to the usual usage an open ma netic circuit is used and its reluctance periodically lowered so as to permit of an inrush of flux and a consequent eneration of current in an adjacent coil due to the momentary bridging of the air gap instead of the common method of generation by increasing the reluctance; to provide a generator of the permanent magnetic type that has pole ends or shoes which have a short magnetic time constant admitting of a greater density of lines than the body of the magnet; that has the least number of parts; that eliminates joints having a high magnectic resistance; that is economical to build and that hall give working voltage at a minimum rate of rotation.

\Vith these and other ends in view I illustrate in the accompanying drawing such instances of adaptaticm as will disclose the broad ideas without limiting myself to the specific features shown.

Figure 1- instances a partial diagrammatic front elevation.

Fig. 2- is a side elevation partly in sec- Fig.3 is a detail elevation of a method of jolning a laminated armature pole to its core.

Fig. 4: is a plan view of another adaptation wherein an armature in connection with the side face of laminar poles is instanced.

Fig. 5- is a diagrammatic view of a magnetic field, without pole shoes. The flux lines across the air gap are shown arbitrarily. At the I point of greatest density fore separating,

the space 18 left blank to contrast the inner and outer paths of magnetic lines with Fig. 6 wherein the pole shoes further concentrate the lines on the inner side of the field magnet when the shoes are opposite the armature poles.

Fig. 6- is a similar view to Fig. 5 with pole shoes attached reducing the leakage lines and concentrating the magnetic flux across the armature area. The magnetic lines are shown arbitrarily as though the armature was in position to span the air gap. The reduction of leakage lines, external of the magnet is shown by the reduced density compared with Fig. 5.

Fig. 7 is a diagrammatic view similar to Fig. 6 with the armature in place and the field approximately at its point of greatest action.

Fig. 8 is a diagrammatic view instancing a permanent magnet serving a series of separate armature coils.

In this type of magneto generator the maximum current is produced when the magnetic circuit is being completed, approximately as shown in Fig. 7 contrary to the usual usage in which this condition is reached when the magnetic circuit has its magnetic resistance suddenly increased without entirely breaking its continuity. As the field magnet 1 is rotated pole ends 2 are bridged by the armature heads and its core a thus causing the stationary armature coil to be subjected to the greatest flux, inducing therein the maximum current potential. Assuming the field to rotate clockwise the poles 2 and 3 will register with each other, beas shown in Fig. 1. Immediately thereafter they will separate and thus substantially break the magnetic circuit leaving it open as shownin Fig. 6.

The field magnet 1 may be built up of more than one unit as shown in Fig. 8 that may be joined in any suitable manner. In-

' stead of the armature comprising a single coil as shown in Fig. lit may be made of any desired number of separate coils, witha pair of pole pieces in common for each of the coils. In which case there would be a distinct successive break in the magnetic field with respect to each armature coil, but

the lines of force would cut all the coils in succession. The magnetic lines of the field magnet 1 successively link'the turns of the coil 5 in a unidirectional manner regardless of the direction in which the magnet is rotated. Fig. 8 instances the use of a series of armature heads 3 attached to core 4, which .when supplied with independent windings 5 between the heads 3 will supply current successively for independent purposes. The presen e of the angular shaped core surrounding the central supporting hub may serve as a keeper to magnet 1 when the same 'is not in rotation.

In the practical use of unit armatures, whether singly or in plurality, there are formed, in regular periodic order, groups of alternate magnetic paths within the curved space or air gap found between the laminated poles 2 of the field magnet 1 as it is rotated. For convenience this space is called the circular air gap. It includes the curved are between pole pieces 2 formed by projecting the same toward each other from a common center also the space between these parts found nearer the center of rotation of the magnet within the radius of the armature poles 3. The first path of each group is of higher reluctance than the second path.

' It is formed each time a single armature head 3 is found in the circular air gap. At such times the longer magnetic path from. one armature head 3 to the other along the core 4 is short circuited and is in parallel relation to that which included pole pieces 2 and a single head 3 mon'ientarily within the flux of the air gap.

The use of projections on the arn'iature heads even though, if taken alone, they do not entirely span the air gap of the field magnet I serve a very useful purpose as results are secured which are not possible without such provision.

These results are found to be a greater E. M. F. at given rotative speeds, a suddenness of impulse, a shortened distance between a pair of projections and an increased length of winding space on account of such projections.

The self induction of the winding 5 largely neutralizes the effect of any leakage that may be present when the coil is in this parallel relation. The rapid change from this position, when an armature head 3 1s 7 in the air gap to that shown in Fig. 1 suddenly forces the entire flux through the armature core at a maximum density. The presence of one of the pole heads 3 within ,the air gap lowers its reluctance so that with a given E. M. F. a large increase of lines will thread the gap immediately before coil action begins. If the rate of circular air gap space to the arc length of a single pole head 3 is too large this beneficial efiect will be minimized, the effect increasing as the heads 3 are lengthened to the ratio shown in Fig. 8 when the magnetic short circuiting of coil- 5 flux density. On account of the diameter permissible in this type of magnetos the rates of travel of the circular air gap at a low speed of rotation is very high in comparison to that required in armatures of the shuttle-type. Consequently, in an exceedingly short interval of timethe established flux, at full density, is swerved to the seond magnetic path, causing an impulse of' reat intensity having'a sharp peak in the characteristic curve instead of the usual sine curve produced by armatures in which a 90 degree change of angular position is required for each revolution at high rotative speed to cause the flux to pass from zero to maximum. Any convenient means of support, as the spider 6 with its hub keyed to shaft 8 may be used. This shaft may have bearing in a hub 9 of armature plate 10 which is fastened by suitable bolts to any desired form of support 11. Plate 10 holds pole pieces 3 and coil 5 in proper relation to the field, whether there be one or -more coils. It is of course immaterial whether the field or the armature is moved so long as there is displacement between them causing the flux to generate a current in the related circuit. It is also immaterial in what axial or radial relation the armature is placed with respect to the field magnet. In Fig. 4 it is shown as placed axially to one side and away from the center of the magnet, ob- \iously the same functions will be performed whether the magnetic lines are swept across the armature axially as in Fig. 4 or radially as in Fig. 1 by reason of the latter being placed outside of the magnet or within it. The farther it is placed from the center of rotation of the magnet the more rapidly the lines will be cut at the same number of revolutions per minute.

Further improvement is reached when the armature shoes'3 and core 4 are also laminated. Additional. benefits arise when the shoes are formed with extensions or horns which project toward each other on one side of the armature coil and toward the path of travel of the field magnet poles 2.

The important feature of these various equivalents lies in there being such a dimensional relation between the pole shoes 3 and the circumferential air gap of the field mag- 'net. as to cause a very liberal and rapid rewill be complete at fullarmature. The greater the change of reluctance that can be made in the air gap of the field magnet through the periodic pressure of the armature shoes the more notable will be the results. Such currents are available for internal combustion engine ignition uses or other purposes as desired.

The pole terminations or pieces 2 may be secured to the ends of magnet 1 in any desired manner so long as the reluctance of the joining faces is not duly increased. The plates may be bolted to each other with nonmagnetic or other, material, a few outside plates may pass over the edges and a few at the center may pass between the magnet units, thus admitting of suitable bolts passing through both and securely holding them in the best magnetic relation.

It is important that a first class junction be made between 00113.4 and pole shoes or heads 3. This may be accomplished as shown in Fig. 3 by squaring the ends of a group of core sections and allowing the pole laminations to encircle the rectangulan ends through the use of short pieces above and below, and clamping the whole together so as to produce a joint of high permeability. These laminated pole ends and core reduce eddy currents and give a potential curve of.

sudden increment and a gradual reduction from its maximum value.

A spark plug 12 and a lamp 13 is shown connected to "the armature circuit 14 from which it may be seen that the specific use to which current produced with magnetos of this or analogous structure is put is immaterial. It does not matter how the current is distributed to various types of multi-cylinder engines.

The armature supports 10 and 11 may be placed in various angular positions with respect to the rotating air gap either advancing or retarding the relation of the one to the other as desired.

The magnet and armature air gaps may also be called circumferential gaps to differentiate them from the radial gaps formed between the outer faces of the stationary armature pole shoes and the adjacent faces of the rotating field magnet poles. The radial gaps are made as small as is found practical while the circumferential gap of the magnet or armature is relatively large.

\Vhat I claim is:

1. In magnetos, an armature comprising a core, a suitable support, a plurality of armature heads secured thereto and provided with curved surfaces disposed to one side of the axis of the core only and projecting tow: rd each other whereby a winding space is formed between the heads and beneath the projections, windings thereon and a. rotating field magnet having projecting pole pieces adapted to be successively moved adjacent the armature heads so as to sweep a unidirectional flux across the windings and generate periodic currents therein.

2. In magnetos, a circularly shaped rotatable field magnet having an air gap therein and projecting poles thereon the said magnet being adapted to move the poles in a circle and on a fixed plane, an armature comprising a support, heads secured thereon, a core connection between pairs of heads, windings on the core, and curved projections of each pair of heads extending toward each other and also adjacent the path of travel of the field magnet poles the ratio of length of a projection to the air gap being such as to greatly reduce the reluctance of the air gap whenever an armature head is found within the flux path traversing from pole to pole whereby periodic impulses are created in the windings through the sweeping of a unidirectional flux across the same as the magnet is rotated.

span the air gap and a pair of heads will form an extended winding space between them without enlarging the distance between the projections of a pair of heads.

1. A unit armature element comprising a plurality of heads, permeable connections constituting a core between said heads, windings on the same, a support for all the parts, and projections from the heads extending toward each other without encroaching on the winding space so that the air gap between the nearest adjacent points of a pair of heads is less than the required length of the winding space.

.5. A magneto armature, comprising a suit able support, a plurality of heads thereon,

core members connected .'to the heads and grouped around a central point on the support, windings between the heads, and projections from the heads extending toward each other on one side of the core members only whereby a lengthened winding space is secured without unduly lengthening the air gap between the projections.

6. In magneto armatures, a suitable support, a. plurality of armature heads carried by the support and provided with curved outer surfaces disposed to one side of the axis of the core and projecting toward each other so as to form a winding space between the heads, a core connecting the heads, and and a rotatable permanent magnet adapted 10 Wmdmgs 0n the core extending into the to sweep a unldirectlonal flux across the space between the core and the PI'OJGCtlOnS. heads in successlve relation.

7. A core member, a plurality of armature In testimony whereof I afiix my signature 5 heads attached to said member, projections i. in presence of two witnesses.

from the heads extending outward and t0- RICHARD A. OGLESBY. Ward each other to one side 'of the core mem- Witnesses: her so as to form a lengthened wirespace ADELINE L. AMsTUTz,

between the heads, windings in such space, C. D. MCLEES. 

